WO2024026868A1

WO2024026868A1 - Sidelink communication coexistence method and apparatus

Info

Publication number: WO2024026868A1
Application number: PCT/CN2022/110675
Authority: WO
Inventors: Ting MIAO; Youxiong Lu; Feng Bi; Weimin XING; Jie Chen
Original assignee: Zte Corporation
Priority date: 2022-08-05
Filing date: 2022-08-05
Publication date: 2024-02-08

Abstract

Methods, apparatus, system for wireless communication are described and include a method of wireless communication that includes determining, by a wireless device, using a rule, validity of one or more feedback resources configured in a time slot for transmission of sidelink feedback information; and performing a sidelink communication based on the determination.

Description

SIDELINK COMMUNICATION COEXISTENCE METHOD AND APPARATUS

TECHNICAL FIELD

This document relates to systems, devices and techniques for wireless communications.

BACKGROUND

Efforts are currently underway to define next generation wireless communication networks that provide greater deployment flexibility, support for a multitude of devices and services and different technologies for efficient bandwidth utilization.

SUMMARY

This document describes technologies, among other things, techniques for coexistence of sidelink communication in a scenario where multiple sidelink protocols are used in a wireless system.

In one example aspect, a method of wireless communication is disclosed. The method includes determining, by a wireless device, using a rule, validity of one or more feedback resources configured in a time slot for transmission of sidelink feedback information; and performing a sidelink communication based on the determination.

In yet another example aspect, a wireless communications apparatus comprising a processor is disclosed. The processor is configured to implement methods described herein.

In another example aspect, the various techniques described herein may be embodied as processor-executable code and stored on a computer-readable program medium.

The details of one or more implementations are set forth in the accompanying drawings, and the description below. Other features will be apparent from the description and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of sidelink slot structures for a New Radio (NR) system and a Long Term Evolution (LTE) system.

FIG. 2 shows an example of sidelink feedback resource assignment in an NR system.

FIG. 3 is a flowchart for an example method of wireless communication.

FIG. 4 is a flowchart for an example method of wireless communication.

FIG. 5 is a block diagram of an example of a wireless communication apparatus.

FIG. 6 shows an example wireless communications network.

DETAILED DESCRIPTION

Section headings are used in the present document only to improve readability and do not limit scope of the disclosed embodiments and techniques in each section to only that section. Furthermore, some embodiments are described with reference to Third Generation Partnership Project (3GPP) New Radio (NR) standard ( “5G” ) for ease of understanding and the described technology may be implemented in different wireless system that implement protocols other than the 5G protocol.

NR sidelink (SL) supports hybrid automatic repeat request (HARQ) feedback and inter-UE coordination (IUC) scheme 2, i.e., NR SL may be configured with physical sidelink feedback channel (PSFCH) for HARQ feedback and conflict information transmission, and PSFCH and physical sidelink control channel/ (PSCCH/PSSCH) are time-division multiplexed in a NR SL slot. However, LTE SL does not support HARQ feedback and not configure PSFCH. Therefore, for LTE SL, PSCCH and PSSCH transmission always occupy the whole SL subframe except the last symbol (the last symbol is a guard symbol) . Therefore, when PSCCH/PSSCH and PSFCH are included in one NR SL slot, LTE SL UE may receive two different NR SL transmissions on a subframe. As a result, the automatic gain control (AGC) training at the beginning of the subframe cannot be applied to the whole subframe. FIG. 1 shows NR SL slot structure and LTE SL subframe structure when sub-carrier spacing (SCS) is 15kHz. When NR SL slot includes both PSCCH/PSSCH and PSFCH, there are two different NR sidelink transmissions in the duration of a LTE sidelink reception, and the power received from the PSCCH/PSSCH transmission could be different from that received from the PSFCH transmission on LTE sidelink devices, that may result in the AGC training in first symbol of LTE sidelink devices is not adaptive to the whole slot of LTE sidelink devices. The communication performance of LTE SL may be affected.

In addition, for the two carriers of NR SL, it is possible that the slot including PSFCH resources in one carrier overlaps with the slot not including PSFCH resources in the other carrier in the time domain, which may also lead to a great change in the received power on the slot not including PSFCH resources for NR SL UE, resulting in the AGC training at the beginning of the slot cannot be applied to the whole slot, resulting in the degradation of SL communication performance. In order to improve communications and meet reliability requirements for SL communication, NR SL communication improvements for sidelink should be made to reduce impact of AGC issue on SL reception performance.

Initial discussion

Sidelink (SL) communication includes: V2X, user equipment (UE) and UE direct communication (e.g., device to device, D2D) , etc. For SL communication, when there is a data to be transmitted between UEs, the data can be directly transmitted from the data source device to the target device without being forwarded by other network devices, that is, to realize the direct communication between devices.

At present, SL communication is mainly based on two radio access technology (RAT) , namely, SL communication based on 4G LTE (long term evolution) technology and 5G NR (new radio) technology. When NR SL and LTE SL are deployed on the same frequency resource, the coexistence between NR SL and LTE SL systems becomes an urgent need. The same frequency resource generally refers to the same carrier or the same frequency band.

NR SL communication support a variety of cast types: broadcast, unicast and groupcast.

For broadcast, the receiver does not perform HARQ feedback.

For unicast and groupcast, whether the receiver needs to perform HARQ feedback depends on whether HARQ feedback is enabled. Where groupcast supports two types: groupcast 1 and groupcast 2.

For unicast, only a specific device is the receiver, and the receiver can transmit ACK/NACK in response to the data reception.

For groupcast 1, only a specific group of devices is the receiver, and the receiver can transmit HARQ-ACK information. However, HARQ-ACK information only includes NACK (i.e., only NACK) . That is, receiver will transmit NACK when the data is decoded incorrectly, and the receiver will not transmit HARQ-ACK information when the data is decoded correctly.

For groupcast 2, only a specific group of devices is the receiver, and the receiver can transmit ACK/NACK in response to the data reception.

NR SL communication supports inter-UE coordination (IUC) . Specifically, UE A sends IUC information to UE B, and UE B perform resource selection based on received IUC information. NR SL supports the following two IUC schemes:

IUC scheme 1: UE A sends preferred resource set or non-preferred resource set to UE B, and UE B performs resource selection based on received resource set. The main purpose is to provide auxiliary information before UE B selects resources, so as to avoid UE B selecting inappropriate resources.

IUC scheme 2: when UE A finds that the reserved resources by UE B are in potential resource conflicts. UE A sends conflict information to UE B. For example, potential resource conflicts include: 1) the reserved resources by UE B overlap with reserved resources by other UE; 2) UE A is the target UE of the transmission block sent by UE B on the reserved resources, but UE A cannot receive on this resource due to half duplex limitation, etc. ICU scheme 2 can be enabled by higher layer signaling, that is, it can be enabled/disabled to transmit conflict information. In addition, UE B can also indicate by sidelink control information (SCI) whether it can receive conflict information.

Control information (e.g., feedback information) provided by a PSFCH transmission includes HARQ-ACK information or conflict information.

Example Embodiments

Some embodiments are disclosed that implement, among other things, determining the validity of PSFCH resources configured in a slot, and determining at least one of the following according to the validity of PSFCH resources: time domain resources used for PSSCH transmission, whether to transmit PSFCH, whether to receive PSFCH, HARQ-ACK information.

Embodiment Example 1:

Several embodiments are now disclosed related to, among other things, determining validity of PSFCH resources.

Embodiment 1-1

In one aspect, this embodiment is related to handling of invalid resources.

In one embodiment, determining the validity of PSFCH resources configured in a slot, includes: if the slot in which PSFCH resources are configured in the first resource pool overlaps with the resources in the second resource pool in time domain, the PSFCH resources configured in the slot are invalid.

In one embodiment, determining the validity of PSFCH resources configured in a slot, includes: if the PSFCH resources overlap with the resources in the second resource pool in time domain, the PSFCH resources configured in the slot are invalid.

Here, the first resource pool is a NR SL resource pool; the second resource pool is an LTE SL resource pool.

FIG. 2 shows an example of validity of PSFCH resources in NR SL resource pool. In this example, PSFCH resource configuration periodicity is 4 slots, it means that one of the four slots includes PSFCH resources. The slots with PSFCH resources are 0, 4, 8. Among them, slot 8 overlaps with the resources in the LTE SL resource pool in time domain. Therefore, the PSFCH resources in slot 8 are invalid.

Embodiment 1-2

In one aspect, this embodiment is related to handling of invalid resources.

In one embodiment, determining the validity of PSFCH resources configured in a slot, includes: if the slot in which PSFCH resources are configured in the first resource pool meets at least one of the following conditions, the PSFCH resources configured in the slot are invalid:

- the slot in which PSFCH resources are configured in the first resource pool overlaps with the resources in the second resource pool in time domain;

- the slot in which PSFCH resources are configured in the first resource pool overlaps with the slot that does not include PSFCH resources in the third resource pool in the time domain.

In one embodiment, determining the validity of PSFCH resources configured in a slot, includes: if the PSFCH resources overlap with the resources in the second resource pool in time domain or overlap with a slot without PSFCH resources in the third resource pool, the PSFCH resources configured in the slot are invalid.

Here, the first resource pool is a NR SL resource pool; the second resource pool is a LTE SL resource pool; the third resource pool is a NR SL resource pool other than the first resource pool.

Embodiment 1-3

In one aspect, this embodiment is related to handling of valid resources.

In one embodiment, determining the validity of PSFCH resources configured in a slot, includes: if the slot in which PSFCH resources are configured in the first resource pool does not overlap with the resources in the second resource pool in time domain, the PSFCH resources configured in the slot are valid.

In one embodiment, determining the validity of PSFCH resources configured in a slot, includes: if the PSFCH resources do not overlap with the resources in the second resource pool in time domain, the PSFCH resources configured in the slot are valid.

Here, the first resource pool is a NR SL resource pool; the second resource pool is a LTE SL resource pool.

Embodiment 1-4

In one aspect, this embodiment is related to handling of valid resources.

In one embodiment, determining the validity of PSFCH resources configured in a slot, includes: if the slot in which PSFCH resources are configured in the first resource pool meets all the following conditions, the PSFCH resources configured in the slot are valid:

- the slot in which PSFCH resources are configured in the first resource pool does not overlap with the resources in the second resource pool in time domain;

- the slot in which PSFCH resources are configured in the first resource pool does not overlap with the slot that does not include PSFCH resources in the third resource pool in the time domain.

In one embodiment, determining the validity of PSFCH resources configured in a slot, includes: if the PSFCH resources do not overlap with the resources in the second resource pool in time domain and do not overlap with a slot without PSFCH resources in the third resource pool, the PSFCH resources configured in the slot are valid.

Embodiment 1-5

In one aspect, this embodiment is related to indicating validity by an indication information.

In one embodiment, determining the validity of PSFCH resources configured in a slot, includes: determining/receiving indication information, determining the validity of PSFCH resources configured in a slot according to the indication information. Here, indication information indicates which of the slots in which PSFCH resources are configured are invalid.

In one embodiment, indication information includes at least one of : the indexes of one or more slots in which PSFCH resources are invalid, the bitmap which indicates one or more slot in which PSFCH resources are invalid.

For example, indicating one or more slot in which PSFCH resources are invalid by bitmap, includes one of the following:

- the length of the bitmap is the total number of slots configured with PSFCH resources in the resource pool. The two states corresponding to each bit in the bitmap are used to indicate whether the PSFCH resources in the slot corresponding to each bit are invalid or valid respectively; For example, a total of 8 slots in the resource pool are configured with PSFCH resources, so the bitmap length is 8 bits. Assuming that the bitmap is 00100001, if 1 indicates that the PSFCH resources in the slot corresponding to the bit are invalid, the PSFCH resources in the 3rd and 8th slots in all slots in which the PSFCH resources are configured are invalid. In other words, the PSFCH resources in the other slots except the 3rd and 8th slots are valid.

- The length of the bitmap is K bits, and the validity of PSFCH resources in every K slots in the slots in which PSFCH resources are configured is indicated by the bitmap; For example, the total number of slots in which PSFCH resources are configured is 12. Assuming K=4 and the bitmap is 0010, the PSFCH resources in the third of every four slots in the 12 slots in which PSFCH resources are configured are invalid, that is, the PSFCH resources in the third, seventh and eleventh slots in all the slots in which PSFCH resources are configured are invalid, and the PSFCH resources in the other slots except third, seventh and eleventh slots are valid.

In one embodiment, indication information can also indicate which of the slots in which PSFCH resources are configured is valid. The method is similar to the above embodiment, which can be described by replacing the word “invalid” with “valid” , and replacing “valid” with “invalid” .

Embodiment 1-6

In one aspect, this embodiment is related to, how, for the slot in which PSFCH resources are invalid, a slot including additional PSFCH resources is determined by configuration or predefined rules.

In one embodiment, the method also includes: for first slot with invalid PSFCH resources in the first resource pool, determining a slot with additional PSFCH resources corresponding to the first slot by configuration or predefined rules.

In one embodiment, determining a slot with additional PSFCH resources corresponding to the first slot by configuration, includes: for first slot in which PSFCH resources are invalid in the first resource pool, if there are one or more second slots in the first resource pool that do not overlap with the resources in the second resource pool in the time domain, and after the first slot, and before the next slot in which PSFCH resources are configured in the first resource pool, determining the slot with additional PSFCH resources is the one of the second slots, otherwise, the first slot has no corresponding slot with additional PSFCH resources.

In one embodiment, determining a slot with additional PSFCH resources corresponding to the first slot by predefined rules, includes: for first slot in which PSFCH resources are invalid in the first resource pool, if there are one or more second slots in the first resource pool that do not overlap with the resources in the second resource pool in the time domain, and after the first slot, and before the next slot in which PSFCH resources are configured in the first resource pool, determining the slot with additional PSFCH resources is the earliest one of the second slots, otherwise, the first slot has no corresponding slot with additional PSFCH resources.

For additional PSFCH resources in a slot, it can be simply understood as: move the PSFCH resources in a slot in which PSFCH resources are invalid to another slot. The PSFCH resources in the another slot after moving are additional PSFCH resources. The mapping relationship between PSSCH and PSFCH resources for HARQ-ACK information transmission in the slot with additional PSFCH resources is the same as that between PSSCH and PSFCH resources for HARQ-ACK information transmission in the slot in which PSFCH resources are invalid The mapping relationship between the reserved resources for PSSCH transmission and PSFCH resources for conflict information transmission in the slot with additional PSFCH resources is the same as that between reserved resources for PSSCH transmission and PSFCH resources for conflict information transmission in the slot in which PSFCH resources are invalid.

Embodiment 1-7

In one aspect, this embodiment relates to features of the second resource pool or the third resource pool.

In one embodiment, the second resource pool includes at least one of: one or more configured LTE SL resource pools, one or more configured LTE SL resource pools related to coexistence, one or more predefined LTE SL resource pools, one or more predefined LTE SL resource pools related to coexistence.

In one embodiment, the third resource pool includes at least one of: one or more configured NR SL resource pools, one or more configured NR SL resource pools with specific features, one or more predefined NR SL resource pools, one or more predefined LTE SL resource pools with specific features.

Here, the specific features include at least one of the following: adjacent to the spectrum of the first resource pool, overlapping with the spectrum of the first resource pool, belonging to the same BWP as the first resource pool, belonging to the same carrier as the first resource pool, and belonging to the same frequency band as the first resource pool.

It should be noted that in the disclosed embodiments, "the PSFCH resource is invalid" or "the PSFCH is invalid" can be that the slot including the PSFCH resources meets the conditions for determining to be invalid, or the PSFCH resource is determined to be invalid through the indication information, or the slot including the PSFCH resources does not meet the conditions for determining to be valid; "PSFCH resource is valid" or "the PSFCH is valid" can be that the slot including the PSFCH resources meets the condition for determining to be valid, or it is determined that the PSFCH resource is valid through the indication information, or the slot including the PSFCH resources does not meet the condition for determining to be invalid.

Embodiment Example 2:

In one aspect, this example relates to the impact of validity on a PSSCH transmission.

Embodiment 2-1

In one aspect, this embodiment discloses rules about symbols that PSSCH cannot use.

In one embodiment, determining symbols used for PSSCH transmission within the slot according to the validity of PSFCH configured in a slot, includes: the UE shall not transmit PSSCH in symbols which are configured for use by PSFCH, if PSFCH is configured and PSFCH is valid in this slot; and the UE shall not transmit PSSCH in the symbol immediately preceding the symbols which are configured for use by PSFCH, if PSFCH is configured and PSFCH is valid in this slot.

For example, UE may transmit the PSSCH in consecutive symbols within the slot, subject to the following restrictions:

- The UE shall not transmit PSSCH in symbols which are not configured for sidelink. A symbol is configured for sidelink, according to higher layer parameters sl-StartSymbol and sl-LengthSymbols, where sl-StartSymbol is the symbol index of the first symbol of sl-LengthSymbols consecutive symbols configured for sidelink.

- Within the slot, PSSCH resource allocation starts at symbol sl-StartSymbol+1.

- The UE shall not transmit PSSCH in symbols which are configured for use by PSFCH, if PSFCH is configured and PSFCH is valid in this slot.

- The UE shall not transmit PSSCH in the last symbol configured for sidelink.

- The UE shall not transmit PSSCH in the symbol immediately preceding the symbols which are configured for use by PSFCH, if PSFCH is configured and PSFCH is valid in this slot.

In one embodiment, determining symbols used for PSSCH reception within the slot according to the validity of PSFCH configured in a slot, includes: the UE does not receive PSSCH in symbols which are configured for use by PSFCH, if PSFCH is configured and PSFCH is valid in this slot; and the UE does not receive PSSCH in the symbol immediately preceding the symbols which are configured for use by PSFCH, if PSFCH is configured and PSFCH is valid in this slot. The example for this embodiment is similar to the above example and may be described by replacing “transmit” in above example with “receive” in this embodiment.

Embodiment 2-2

In one aspect, this embodiment relates to handling of symbols that PSSCH cannot use.

In one embodiment, determining symbols used for PSSCH transmission within the slot according to the validity of PSFCH configured in a slot, includes: the UE shall not transmit PSSCH in symbols which are configured for use by PSFCH, if PSFCH is configured and PSFCH is valid in this slot, or there is additional PSFCH in this slot; and the UE shall not transmit PSSCH in the symbol immediately preceding the symbols which are configured for use by PSFCH, if PSFCH is configured and PSFCH is valid in this slot, or there is additional PSFCH in this slot.

For example, UE shall transmit the PSSCH in consecutive symbols within the slot, subject to the following restrictions:

- Within the slot, PSSCH resource allocation starts at symbol sl-StartSymbol+1.

- The UE shall not transmit PSSCH in symbols which are configured for use by PSFCH, if PSFCH is configured and PSFCH is valid in this slot, or there is additional PSFCH in this slot.

- The UE shall not transmit PSSCH in the last symbol configured for sidelink.

- The UE shall not transmit PSSCH in the symbol immediately preceding the symbols which are configured for use by PSFCH, if PSFCH is configured and PSFCH is valid in this slot, or there is additional PSFCH in this slot.

In one embodiment, determining symbols used for PSSCH reception within the slot according to the validity of PSFCH configured in a slot, includes: the UE may not receive PSSCH in symbols which are configured for use by PSFCH, if PSFCH is configured and PSFCH is valid in this slot, or there is additional PSFCH in this slot; and the UE may not receive PSSCH in the symbol immediately preceding the symbols which are configured for use by PSFCH, if PSFCH is configured and PSFCH is valid in this slot, or there is additional PSFCH in this slot. The example for this embodiment is similar to the above example and may be described by replacing “transmit” in above example with “receive” in this embodiment.

Embodiment 2-3

In one aspect, this embodiment relates to rules about symbols that PSSCH cannot use.

In one embodiment, determining symbols used for PSSCH transmission within the slot according to the validity of PSFCH configured in a slot, includes: the UE transmits PSSCH in symbols from symbol sl-StartSymbol+1 to symbol sl-StartSymbol+sl-LengthSymbols-2 within the slot, if PSFCH is configured and PSFCH is invalid in this slot; otherwise, the UE transmits PSSCH in symbols from symbol sl-StartSymbol+1 to symbol sl-StartSymbol+sl-LengthSymbols-X-3 (or sl-StartSymbol+sl-LengthSymbols-5 ) within the slot, where, sl-StartSymbol is the symbol index of the first symbol of sl-LengthSymbols consecutive symbols configured for sidelink, X is the number of symbols which are configured for use by PSFCH.

In one embodiment, determining symbols used for PSSCH reception within the slot according to the validity of PSFCH configured in a slot, includes: the UE receives PSSCH in symbols from symbol sl-StartSymbol+1 to symbol sl-StartSymbol+sl-LengthSymbols-2 within the slot, if PSFCH is configured and PSFCH is invalid in this slot; otherwise, the UE receives PSSCH in symbols from symbol sl-StartSymbol+1 to symbol sl-StartSymbol+sl-LengthSymbols-X-3 (or sl-StartSymbol+sl-LengthSymbols-5 ) within the slot, where, sl-StartSymbol is the symbol index of the first symbol of sl-LengthSymbols consecutive symbols configured for sidelink, X is the number of symbols which are configured for use by PSFCH.

Embodiment 2-4

In one embodiment, determining symbols used for PSSCH transmission within the slot according to the validity of PSFCH configured in a slot, includes: the UE transmits PSSCH in symbols from symbol sl-StartSymbol+1 to symbol sl-StartSymbol+sl-LengthSymbols-2 within the slot, if PSFCH is configured and PSFCH is invalid in this slot , or if PSFCH is not configured and there is no additional PSFCH in this slot; otherwise, the UE transmits PSSCH in symbols from symbol sl-StartSymbol+1 to symbol sl-StartSymbol+sl-LengthSymbols-X-3 (or sl-StartSymbol+sl-LengthSymbols-5 ) within the slot, where, sl-StartSymbol is the symbol index of the first symbol of sl-LengthSymbols consecutive symbols configured for sidelink, X is the number of symbols which are configured for use by PSFCH.

In one embodiment, determining symbols used for PSSCH reception within the slot according to the validity of PSFCH configured in a slot, includes: the UE receives PSSCH in symbols from symbol sl-StartSymbol+1 to symbol sl-StartSymbol+sl-LengthSymbols-2 within the slot, if PSFCH is configured and PSFCH is invalid in this slot , or if PSFCH is not configured and there is no additional PSFCH in this slot; otherwise, the UE receives PSSCH in symbols from symbol sl-StartSymbol+1 to symbol sl-StartSymbol+sl-LengthSymbols-X-3 (or sl-StartSymbol+sl-LengthSymbols-5 ) within the slot, where, sl-StartSymbol is the symbol index of the first symbol of sl-LengthSymbols consecutive symbols configured for sidelink, X is the number of symbols which are configured for use by PSFCH.

Embodiment Example 3:

This section discloses various aspects of impact of validity of resources on PSFCH transmission or reception.

Embodiment 3-1

In one aspect, this embodiment relates to impact of validity of resources on PSFCH transmission.

In one embodiment, determining to transmit PSFCH according to the validity of PSFCH configured in a slot, includes: if a UE receives a PSSCH in a resource pool, and associated SCI indicates the HARQ feedback is enabled, and PSFCH resource corresponding to the PSSCH is valid, the UE provides the HARQ-ACK information in this PSFCH resource.

For example, if a UE receives a PSSCH in a resource pool and the HARQ feedback enabled/disabled indicator field in an associated SCI format 2-A/2-B/2-C has value 1 (i.e. HARQ feedback is enabled) , the UE provides the HARQ-ACK information in a PSFCH transmission in the resource pool. The UE transmits the PSFCH in a first slot that includes valid PSFCH resources and is at least a number of slots, provided by sl-MinTimeGapPSFCH, of the resource pool after a last slot of the PSSCH reception.

In one embodiment, determining to transmit PSFCH according to the validity of PSFCH configured in a slot, includes: if the UE determines a conflict for a reserved resource for PSSCH transmission, and PSFCH corresponding to the reserved resource for PSSCH transmission is valid, the UE provides conflict information in the PSFCH.

For example, a UE can be enabled, by inter-UECoordinationScheme2, to transmit a PSFCH with conflict information in a resource pool. The UE can determine, based on an indication by a SCI format 1-A, a set of resources that includes one or more slots and resource blocks that are reserved for PSSCH transmission. If the UE determines a conflict for a reserved resource for PSSCH transmission and PSFCH corresponding to the reserved resource for PSSCH transmission is valid, the UE provides conflict information in the PSFCH.

Embodiment 3-2

In one aspect, this embodiment relates to impact of validity of resources on a PSFCH transmission.

In one embodiment, determining to transmit PSFCH according to the validity of PSFCH configured in a slot, includes: if a UE receives a PSSCH in a resource pool, and associated SCI indicates the HARQ feedback is enabled, and PSFCH resource corresponding to the PSSCH is valid or there is additional PSFCH corresponding to the PSSCH, the UE provides the HARQ-ACK information in this PSFCH resource.

For example, if a UE receives a PSSCH in a resource pool and the HARQ feedback enabled/disabled indicator field in an associated SCI format 2-A/2-B/2-C has value 1 (i.e., HARQ feedback is enabled) , the UE provides the HARQ-ACK information in a PSFCH transmission in the resource pool. The UE transmits the PSFCH in a first slot that includes valid PSFCH resources and is at least a number of slots, provided by sl-MinTimeGapPSFCH, of the resource pool after a last slot of the PSSCH reception; or the UE transmits the PSFCH in a slot with additional PSFCH resources corresponding to a first slot includes invalid PSFCH resources and is at least a number of slots, provided by sl-MinTimeGapPSFCH, of the resource pool after a last slot of the PSSCH reception.

In one embodiment, determining to transmit PSFCH according to the validity of PSFCH configured in a slot, includes: if the UE determines a conflict for a reserved resource for PSSCH transmission, and PSFCH corresponding to the reserved resource for PSSCH transmission is valid or there is additional PSFCH corresponding to the reserved resource for PSSCH transmission, the UE provides conflict information in the PSFCH.

For example, a UE can be enabled, by inter-UECoordinationScheme2, to transmit a PSFCH with conflict information in a resource pool. The UE can determine, based on an indication by a SCI format 1-A, a set of resources that includes one or more slots and resource blocks that are reserved for PSSCH transmission. If the UE determines a conflict for a reserved resource for PSSCH transmission, and PSFCH corresponding to the reserved resource for PSSCH transmission is valid or there is additional PSFCH corresponding to the reserved resource for PSSCH transmission, the UE provides conflict information in the PSFCH.

Embodiment 3-3

In one aspect, this embodiment relates to impact of validity of resources on a PSFCH transmission, specifically related to rules of non-transmission.

In one embodiment, determining not to transmit PSFCH according to the validity of PSFCH configured in a slot, includes at least one of:

- if a UE receives a PSSCH in a resource pool, and PSFCH resource corresponding to the PSSCH is invalid, the UE does not transmit PSFCH with HARQ-ACK information in this PSFCH resource

- if a UE receives a PSSCH in a resource pool, and PSFCH resource corresponding to the PSSCH is invalid and there is no additional PSFCH corresponding to the PSSCH, the UE does not transmit PSFCH with HARQ-ACK information in this PSFCH resource.

- if the UE determines a conflict for a reserved resource for PSSCH transmission, and PSFCH is invalid corresponding to the reserved resource for PSSCH transmission, the UE does not transmit PSFCH with conflict information in this PSFCH resource

- if the UE determines a conflict for a reserved resource for PSSCH transmission, and PSFCH is invalid corresponding to the reserved resource for PSSCH transmission and there is no additional PSFCH corresponding to the reserved resource for PSSCH transmission, the UE does not transmit PSFCH with conflict information in this PSFCH resource.

Embodiment 3-4

In one aspect, this embodiment relates to impact of validity of resources on PSFCH reception, specifically related to receiving the message.

In one embodiment, determining to receive PSFCH according to the validity of PSFCH configured in a slot, includes: a UE that transmitted a PSSCH scheduled by a SCI that indicates HARQ feedback enabled, attempts to receive associated physical sidelink feedback channel PSFCHs with HARQ-ACK information in the PSFCH if PSFCH corresponding to the PSSCH is valid.

For example, a UE that transmitted a PSSCH scheduled by a SCI format 2-A/2-B/2-C that indicates HARQ feedback enabled, attempts to receive associated PSFCHs with HARQ-ACK information according to PSFCH resources determined as described in clause 16.3.0 in TS38.213 if PSFCH corresponding to the PSSCH is valid.

In one embodiment, determining to receive PSFCH according to the validity of PSFCH configured in a slot, includes: a UE that transmitted SCI format 1-A, indicating one or more reserved resources in a resource pool enabled by inter-UECoordinationScheme2 (i.e., inter-UE coordination scheme 2 is enable) , attempts to receive associated PSFCH with conflict information in the PSFCH if PSFCH corresponding to the reserved resource (or resources) for PSSCH transmission is valid.

For example, a UE that transmitted SCI format 1-A, indicating one or more reserved resources in a resource pool enabled by inter-UECoordinationScheme2, attempts to receive associated PSFCH with conflict information in a resource pool with PSFCH resources that the UE determines as described in clause 16.3.0 in TS38.213 if PSFCH corresponding to the reserved resource (s) for PSSCH transmission is valid.

Embodiment 3-5

In one embodiment, determining to receive PSFCH according to the validity of PSFCH configured in a slot, includes: a UE that transmitted a PSSCH scheduled by a SCI that indicates HARQ feedback enabled, attempts to receive associated PSFCHs with HARQ-ACK information in the PSFCH if PSFCH corresponding to the PSSCH is valid or there is additional PSFCH corresponding to the PSSCH.

For example, a UE that transmitted a PSSCH scheduled by a SCI format 2-A/2-B/2-C that indicates HARQ feedback enabled, attempts to receive associated PSFCHs with HARQ-ACK information according to PSFCH resources determined as described in clause 16.3.0 in TS38.213 if PSFCH corresponding to the PSSCH is valid or there is additional PSFCH corresponding to the PSSCH.

In one embodiment, determining to receive PSFCH according to the validity of PSFCH configured in a slot, includes: a UE that transmitted SCI format 1-A, indicating one or more reserved resources in a resource pool in which inter-UE coordination scheme 2 is enable, attempts to receive associated PSFCH with conflict information in the PSFCH if PSFCH corresponding to the reserved resource (or resources) for PSSCH transmission is valid or there is additional PSFCH corresponding to the reserved resource (or resources) for PSSCH transmission.

For example, a UE that transmitted SCI format 1-A, indicating one or more reserved resources in a resource pool enabled by higher layer parameter inter-UECoordinationScheme2 (i.e. inter-UE coordination scheme 2 is enable) , attempts to receive associated PSFCH with conflict information in a resource pool with PSFCH resources that the UE determines as described in clause 16.3.0 in TS38.213 if PSFCH corresponding to the reserved resource (s) for PSSCH transmission is valid or there is additional PSFCH corresponding to the reserved resource (or resources) for PSSCH transmission.

Embodiment 3-6

In one aspect, this embodiment relates to impact of validity of resources on PSFCH reception, specifically related to rules of non-reception.

In one embodiment, determining to not to receive PSFCH according to the validity of PSFCH configured in a slot, includes at least one of:

- a UE that transmitted the PSSCH scheduled by a SCI, does not receive associated PSFCHs with HARQ-ACK information in the PSFCH if PSFCH resource corresponding to the PSSCH is invalid.

- a UE that transmitted the PSSCH scheduled by a SCI, does not receive associated PSFCHs with HARQ-ACK information in the PSFCH if PSFCH resource corresponding to the PSSCH is invalid and there is no additional PSFCH corresponding to the PSSCH.

- a UE that transmitted SCI format 1-A, indicating one or more reserved resources, does not receive associated PSFCH with conflict information in the PSFCH if PSFCH corresponding to the reserved resource (or resources) for PSSCH transmission is invalid

- a UE that transmitted SCI format 1-A, indicating one or more reserved resources, does not receive associated PSFCH with conflict information in the PSFCH if PSFCH corresponding to the reserved resource (or resources) for PSSCH transmission is invalid and there is additional PSFCH corresponding to the reserved resource (or resources) for PSSCH transmission.

Embodiment Example 4:

This section describes, among other things, impact of validity on generating the HARQ-ACK information.

Embodiment 4-1

This embodiment relates to, in one aspect, impact of validity on generating the HARQ-ACK information reported to higher layers. Herein, “higher layer” refers to a protocol stack layer above physical layer, and may refer to the protocol stack within the UE itself.

In one embodiment, generating the HARQ-ACK information according to the validity of PSFCH configured in a slot, includes: if the PSFCH reception occasion is associated with a SCI that indicates cast type is groupcast 1 and PSFCH is valid in the PSFCH reception occasion, report to higher layers an ACK value if the UE determines absence of PSFCH reception for the PSFCH reception occasion; otherwise, report a NACK value to higher layers.

For example, for each PSFCH reception occasion, from a number of PSFCH reception occasions, the UE generates HARQ-ACK information to report to higher layers. For generating the HARQ-ACK information, the UE can be indicated by a SCI format to perform one of the following

- if the UE receives a PSFCH associated with a SCI format 2-A with Cast type indicator field value of "10" or a SCI format 2-C (i.e., broadcast)

- report to higher layers HARQ-ACK information with same value as a value of HARQ-ACK information that the UE determines from the PSFCH reception

- if the UE receives a PSFCH associated with a SCI format 2-A with Cast type indicator field value of "01" (i.e., groupcast 2)

- report an ACK value to higher layers if the UE determines an ACK value from at least one PSFCH reception occasion from the number of PSFCH reception occasions in PSFCH resources corresponding to every identity M _ID of UEs that the UE expects to receive corresponding PSSCHs as described in clause 16.3 in TS38.213; otherwise, report a NACK value to higher layers

- if the PSFCH reception occasion is associated with a SCI format 2-B or a SCI format 2-Awith Cast type indicator field value of "11" (i.e. groupcast 1) and PSFCH is valid in the PSFCH reception occasion,

-, report to higher layers an ACK value if the UE determines absence of PSFCH reception for the PSFCH reception occasion; otherwise, report a NACK value to higher layers

Embodiment 4-2

This embodiment relates to, in one aspect, impact of validity on generating the HARQ-ACK information reported to higher layers.

In one embodiment, generating the HARQ-ACK information according to the validity of PSFCH configured in a slot, includes: For generating the HARQ-ACK information, the UE can be indicated by a SCI format to perform one of the following

- when PSFCH is valid in the PSFCH reception occasion, if the UE receives a PSFCH associated with a SCI that indicates cast type is broadcast, report to higher layers HARQ-ACK information with same value as a value of HARQ-ACK information that the UE determines from the PSFCH reception; when PSFCH is invalid in the PSFCH reception occasion, report a NACK value to higher layers

- when PSFCH is valid in the PSFCH reception occasion, if the UE receives a PSFCH associated with a SCI that indicates cast type is groupcast 2, report an ACK value to higher layers if the UE determines an ACK value from at least one PSFCH reception occasion from the number of PSFCH reception occasions in PSFCH resources corresponding to every identity M _ID of UEs that the UE expects to receive corresponding PSSCHs, otherwise, report a NACK value to higher layers; when PSFCH is invalid in the PSFCH reception occasion, report a NACK value to higher layers

- when PSFCH is valid in the PSFCH reception occasion, if the PSFCH reception occasion is associated with a SCI that indicates cast type is groupcast 2, report to higher layers an ACK value if the UE determines absence of PSFCH reception for the PSFCH reception occasion; otherwise, report a NACK value to higher layers; when PSFCH is invalid in the PSFCH reception occasion, report a NACK value to higher layers

Embodiment 4-3

- when PSFCH is valid in the PSFCH reception occasion, if the UE receives a PSFCH associated with a SCI that indicates cast type is broadcast, report to higher layers HARQ-ACK information with same value as a value of HARQ-ACK information that the UE determines from the PSFCH reception; when PSFCH is invalid in the PSFCH reception occasion, report third feedback state to higher layers

- when PSFCH is valid in the PSFCH reception occasion, if the UE receives a PSFCH associated with a SCI that indicates cast type is groupcast 2, report an ACK value to higher layers if the UE determines an ACK value from at least one PSFCH reception occasion from the number of PSFCH reception occasions in PSFCH resources corresponding to every identity M _ID of UEs that the UE expects to receive corresponding PSSCHs, otherwise, report a NACK value to higher layers; when PSFCH is invalid in the PSFCH reception occasion, report third feedback state to higher layers

- when PSFCH is valid in the PSFCH reception occasion, if the PSFCH reception occasion is associated with a SCI that indicates cast type is groupcast 2, report to higher layers an ACK value if the UE determines absence of PSFCH reception for the PSFCH reception occasion; otherwise, report a NACK value to higher layers; when PSFCH is invalid in the PSFCH reception occasion, report third feedback state to higher layers

It is worth noting that the third feedback state is a state that is neither ACK nor NACK, which is used by the higher layers to determine the HARQ-ACK information delivered to the corresponding HARQ entity. For example, if the higher layers obtain the third feedback state from the physical layer, it delivers NACK to the corresponding HARQ entity. The invention does not limit the method of determining HARQ-ACK information according to the third feedback state.

Embodiment 4-4

This embodiment relates to, in one aspect, impact of validity on generating the HARQ-ACK information for reporting in a physical uplink control channel PUCCH or physical uplink shared channel PUSCH transmission.

In one embodiment, generating the HARQ-ACK information according to the validity of PSFCH configured in a slot, includes: for one or more PSFCH reception occasions associated with SCI that indicates cast type is groupcast 1, generate ACK when the UE determines absence of PSFCH reception for the last valid PSFCH reception occasion from the number of PSFCH reception occasions corresponding to PSSCH transmissions; otherwise, generate NACK.

For example, from a number of PSFCH reception occasions, the UE generates

HARQ-ACK information to report in a PUCCH or PUSCH transmission. The UE can be indicated by a SCI format to perform one of the following and the UE constructs a HARQ-ACK codeword with HARQ-ACK information, when applicable.

- for one or more PSFCH reception occasions associated with SCI format 2-A with Cast type indicator field value of "10" (i.e., broadcast)

- generate HARQ-ACK information with same value as a value of HARQ-ACK information the UE determines from the last PSFCH reception from the number of PSFCH reception occasions corresponding to PSSCH transmissions or, if the UE determines that a PSFCH is not received at the last PSFCH reception occasion and ACK is not received in any of previous PSFCH reception occasions, generate NACK

- for one or more PSFCH reception occasions associated with SCI format 2-A with Cast type indicator field value of "01" (i.e., groupcast 2)

- generate ACK if the UE determines ACK from at least one PSFCH reception occasion, from the number of PSFCH reception occasions corresponding to PSSCH transmissions, in PSFCH resources corresponding to every identity M _ID of the UEs that the UE expects to receive the PSSCH, as described in clause 16.3 in TS38.213; otherwise, generate NACK

- for one or more PSFCH reception occasions associated with SCI format 2-B or SCI format 2-A with Cast type indicator field value of "11" (i.e. groupcast 1)

- generate ACK when the UE determines absence of PSFCH reception for the last valid PSFCH reception occasion from the number of PSFCH reception occasions corresponding to PSSCH transmissions; otherwise, generate NACK

In one embodiment, generating the HARQ-ACK information according to the validity of PSFCH configured in a slot, includes: for one or more PSFCH reception occasions associated with SCI that indicates cast type is groupcast 1, generate ACK when the UE determines absence of PSFCH reception for the last PSFCH reception occasion from the number of valid PSFCH reception occasions corresponding to PSSCH transmissions; otherwise, generate NACK. The example is similar to the above example and may be described by replacing “scheme corresponding to groupcast 1” in above example with the scheme in this embodiment.

Embodiment 4-5

This embodiment relates to, in one aspect, impact of validity on generating the HARQ-ACK information for reporting in a PUCCH or PUSCH transmission.

In one embodiment, generating the HARQ-ACK information according to the validity of PSFCH configured in a slot, includes: from a number of PSFCH reception occasions, the UE generates HARQ-ACK information to report in a PUCCH or PUSCH transmission. The UE can be indicated by a SCI format to perform one of the following and the UE constructs a HARQ-ACK codeword with HARQ-ACK information, when applicable.

- for one or more PSFCH reception occasions associated with SCI that indicates cast type is broadcast

- generate HARQ-ACK information with same value as a value of HARQ-ACK information the UE determines from the last PSFCH reception from the number of valid PSFCH reception occasions corresponding to PSSCH transmissions or, if the UE determines that a PSFCH is not received at the last valid PSFCH reception occasion and ACK is not received in any of previous valid PSFCH reception occasions, generate NACK

- for one or more PSFCH reception occasions associated with SCI that indicates cast type is groupcast 2

- generate ACK if the UE determines ACK from at least one PSFCH reception occasion, from the number of valid PSFCH reception occasions corresponding to PSSCH transmissions, in PSFCH resources corresponding to every identity M _ID of the UEs that the UE expects to receive the PSSCH; otherwise, generate NACK

- for one or more PSFCH reception occasions associated with SCI that indicates cast type is groupcast 1

- generate ACK when the UE determines absence of PSFCH reception for the last PSFCH reception occasion from the number of valid PSFCH reception occasions corresponding to PSSCH transmissions; otherwise, generate NACK

In one embodiment, generating the HARQ-ACK information according to the validity of PSFCH configured in a slot, includes: from a number of PSFCH reception occasions, the UE generates HARQ-ACK information to report in a PUCCH or PUSCH transmission. The UE can be indicated by a SCI format to perform one of the following and the UE constructs a HARQ-ACK codeword with HARQ-ACK information, when applicable

- generate HARQ-ACK information with same value as a value of HARQ-ACK information the UE determines from the last valid PSFCH reception from the number of PSFCH reception occasions corresponding to PSSCH transmissions or, if the UE determines that a PSFCH is not received at the last valid PSFCH reception occasion and ACK is not received in any of previous valid PSFCH reception occasions, generate NACK

- generate ACK if the UE determines ACK from at least one valid PSFCH reception occasion, from the number of PSFCH reception occasions corresponding to PSSCH transmissions, in PSFCH resources corresponding to every identity M _ID of the UEs that the UE expects to receive the PSSCH; otherwise, generate NACK

In one embodiment, a slot in which PSFCH is configured refers to the slot including PSFCH resources provided by periodic PSFCH configuration (for example, provided by higher layer parameter sl-PSFCH-Period) .

In one embodiment, the slot in which PSFCH is configured and valid includes at least one of the following:

- a slot in which PSFCH is configured by periodic PSFCH configuration, and that does not meet the condition of determining that the PSFCH resources in the slot are invalid;

- a slot in which PSFCH is configured by periodic PSFCH configuration, and that meets the condition of determining that the PSFCH resources in the slot are valid;

- a slot among a number of slots in which PSFCH is configured by periodic PSFCH configuration, and PSFCH in the slot is indicated as valid by the indication information;

- a slot that includes additional PSFCH resources.

In one embodiment, the slot in which PSFCH is configured and invalid includes at least one of the following:

- a slot in which PSFCH is configured by periodic PSFCH configuration, and that meets the condition of determining that the PSFCH resources in the slot are invalid;

- a slot in which PSFCH is configured by periodic PSFCH configuration, and that does not meet the condition of determining that the PSFCH resources in the slot are valid;

- a slot among a number of slots in which PSFCH is configured by periodic PSFCH configuration, and PSFCH in the slot is indicated as invalid by the indication information.

In one embodiment, valid PSFCH includes at least one of the following:

- PSFCH is in a slot that does not meet the condition of determining that the PSFCH resources in the slot are invalid;

- PSFCH is in a slot that meets the condition of determining that the PSFCH resources in the slot are valid;

- PSFCH is in a slot in which PSFCH is valid indicated by the indication information;

- additional PSFCH.

In one embodiment, invalid PSFCH includes at least one of the following:

- PSFCH is in a slot that does not meet the condition of determining that the PSFCH resources in the slot are valid;

- PSFCH is in a slot that meets the condition of determining that the PSFCH resources in the slot are invalid;

- PSFCH is in a slot in which PSFCH is invalid indicated by the indication information;

Similar to “valid PSFCH, ” in one embodiment, valid PSFCH reception occasion includes at least one of the following:

- PSFCH reception occasion is in a slot that does not meet the condition of determining that the PSFCH resources in the slot are invalid;

- PSFCH reception occasion is in a slot that meets the condition of determining that the PSFCH resources in the slot are valid;

- PSFCH reception occasion is in a slot in which PSFCH is valid indicated by the indication information;

- PSFCH reception occasion corresponding to additional PSFCH.

In one embodiment, configuring a certain information usually means that the network or base station configures the information to the UE; preconfiguring a certain information usually means that other higher layer entities (such as UE's own higher layers, other network entities, etc. ) configure the information to UE. The present description does not strictly distinguish between configuration and preconfiguration. For the convenience of description, both configuration and preconfiguration are collectively referred to as configuration. In other words, “configuring some information” means “configuring/preconfiguring some information” , “some information is configured” means “some information is configured/preconfigured” .

Some preferred embodiments may incorporate the following solutions. In the solutions, the term “communication” may refer to “transmission” or “reception” as further disclosed in the present document.

The first set of solutions may be implemented by wireless device embodiments that send a PSSCH transmission and receive sidelink feedback corresponding to the PSSCH.

1. A method of wireless communication (e.g., method 300 depicted in FIG. 3) , comprising: determining (302) , by a wireless device, using a rule, validity of one or more feedback resources configured in a time slot for transmission of sidelink feedback information; and performing (304) a sidelink communication based on the determination. Various examples of this method are described with reference to Embodiments 1 to 4.

2. The method of solution 1, wherein, according to the rule, in case that the one or more feedback resources that are configured in a first resource pool overlap with a second resource pool in time domain, or the time slot that includes the one or more feedback resources in the first resource pool overlaps with the second resource pool, then the one or more feedback resources are considered to be invalid.

3. The method of solution 1, wherein, according to a rule, the validity is determined using an indication information configured in a first resource pool.

4. The method of any of solutions 1-3, wherein the one or more feedback resources are included in a first slot and wherein, in case that the one or more feedback resources are determined to be invalid, the method further includes determining a second slot that includes additional one or more feedback resources corresponding to the first slot. Additional details and examples are described with reference to Embodiment 1-6.

5. The method of any of solutions 1-4, wherein the performing the sidelink communication based on the determination includes: in case that the one or more feedback resources are valid, then refraining from transmitting a physical sidelink shared channel in one or more symbols configured as the one or more feedback resources in the time slot, and refraining from transmitting the physical sidelink shared channel in a symbol immediately preceding the one or more symbols configured as the feedback resources in the time slot. Additional details and examples are described with reference to Embodiment 2-1.

6. The method of any of solutions 1-4, wherein the performing the sidelink communication based on the determination, includes: in case that the one or more feedback resources are included in the time slot and the feedback resources are valid, or additional one or more feedback resources are included in the time slot, then refraining from transmitting a physical sidelink shared channel in one or more symbols configured as the one or more feedback resources in the time slot, and refraining from transmitting the physical sidelink shared channel in a symbol immediately preceding the one or more symbols configured as the one or more feedback resources in the time slot. Additional details and examples are described with reference to Embodiment 2-2.

7. The method of any of solutions 1-4, wherein the performing the sidelink communication based on the determination includes: attempting to receive one or more associated sidelink feedback information in case that following conditions are met: (1) a physical sidelink shared channel (PSSCH) has been transmitted, (2) sidelink control information associated with the PSSCH indicates that the feedback mode is enabled, and (3) one or more feedback resources for receiving the sidelink feedback information corresponding to the PSSCH are valid. Additional details and examples are described with reference to Embodiment 3-4.

8. The method of any of solutions 1-4, wherein the performing the sidelink communication based on the determination includes: attempting to receive one or more associated sidelink feedback information in case that following conditions are met: (1) a physical sidelink control information (SCI) has been transmitted, (2) the SCI indicates one or more reserved resources for PSSCH in a resource pool, (3) an inter-UE coordination scheme 2 is enabled in the resource pool, and (4) one or more feedback resources for receiving the sidelink feedback information corresponding to the reserved resource for PSSCH are valid. Additional details and examples are described with reference to Embodiment 3-4.

9. The method of any of solutions 1-4, wherein the performing the sidelink communication based on the determination includes: attempting to receive one or more associated feedback information in case that following conditions are met: (1) a physical sidelink shared channel (PSSCH) has been transmitted, (2) sidelink control information associated with the PSSCH indicates that the feedback mode is enabled, and (3) one or more feedback resources for receiving the sidelink feedback information corresponding to the PSSCH are valid, or there are additional one or more feedback resources corresponding to the PSSCH. Additional details and examples are described with reference to Embodiment 3-5.

10. The method of any of solutions 1-4, wherein the performing the sidelink communication based on the determination includes: attempting to receive one or more associated sidelink feedback information in case that following conditions are met: (1) a physical sidelink control information (SCI) has been transmitted, (2) the SCI indicates one or more reserved resources for a physical sidelink shared channel (PSSCH) in a resource pool, (3) an inter-UE coordination scheme 2 is enabled in the resource pool, and (4) one or more feedback resources for receiving the sidelink feedback information corresponding to the reserved resource for PSSCH are valid, or there are additional one or more feedback resources corresponding to the reserved resource for PSSCH. Additional details and examples are described with reference to Embodiment 3-5.

11. The method of any of solutions 1-4, wherein the performing the sidelink communication based on the determination includes: in case that a feedback information reception occasion is associated with a sidelink control information (SCI) that indicates a cast type is groupcast 1 and one or more feedback resources in the feedback information reception occasion are valid, reporting as follows: reporting, in case that the wireless device determines absence of feedback information reception for the feedback information reception occasion, an ACK value to a higher layer; otherwise, reporting a NACK value to the higher layer. Additional details and examples are described with reference to Embodiment 4-1.

12. The method of any of solutions 1-4, wherein the performing the sidelink communication based on the determination includes: for one or more feedback information reception occasions associated with a sidelink control information (SCI) that indicates a cast type is groupcast 1, generating an ACK when the wireless device determines absence of feedback information reception for a last valid feedback information reception occasion from a number of feedback information reception occasions corresponding to one or more physical sidelink shared channel (PSSCH) transmissions; otherwise, generating a NACK; and transmitting a generated information by a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH) . Additional details and examples are described with reference to Embodiment 4-4.

Another set of preferred embodiments may be as follows.

The second set of solutions may be implemented by wireless device embodiments that receive a PSSCH transmission and send sidelink feedback corresponding to the PSSCH.

1. A method of wireless communication (e.g., method 400 depicted in FIG. 4) , comprising: determining (402) , by a wireless device, using a rule, validity of one or more feedback resources configured in a time slot for transmission of sidelink feedback information; and performing (404) a sidelink communication based on the determination.

5. The method of any of solutions 1-4, wherein the performing the sidelink communication based on the determination includes: in case that the one or more feedback resources are valid, then refraining from receiving a physical sidelink shared channel in one or more symbols configured as the one or more feedback resources in the time slot, and refraining from receiving the physical sidelink shared channel in a symbol immediately preceding the one or more symbols configured as the feedback resources in the time slot. Additional details and examples are described with reference to Embodiment 2-1.

6. The method of any of solutions 1-4, wherein the performing the sidelink communication based on the determination, includes: in case that the one or more feedback resources are included in the time slot and the feedback resources are valid, or additional one or more feedback resources are included in the time slot, then refraining from receiving a physical sidelink shared channel in one or more symbols configured as the one or more feedback resources in the time slot, and refraining from receiving the physical sidelink shared channel in a symbol immediately preceding the one or more symbols configured as the one or more feedback resources in the time slot. Additional details and examples are described with reference to Embodiment 2-2.

7. The method of any of solutions 1-4, wherein the performing the sidelink communication based on the determination, includes: transmitting sidelink feedback information in case that following conditions are met: (1) a physical sidelink shared channel (PSSCH) is received, (2) sidelink control information indicates that the feedback mode is enabled, and (3) the one or more feedback resources for transmitting a feedback information corresponding to the physical shared sidelink channel are valid. Additional details and examples are described with reference to Embodiment 3-1.

8. The method of any of solutions 1-4, wherein the performing the sidelink communication based on the determination includes: transmitting sidelink feedback information in case that following conditions are met: (1) determining that there is a conflict for a reserved resource for a physical sidelink shared channel (PSSCH) transmission, and (2) the one or more feedback resources for transmitting the sidelink feedback information corresponding to the PSSCH are valid. Additional details and examples are described with reference to Embodiment 3-1.

9. The method of any of solutions 1-4, wherein the performing the sidelink communication based on the determination includes: transmitting the sidelink feedback information in case that following conditions are met: (1) a physical sidelink shared channel is received, (2) sidelink control information associated with the physical sidelink shared channel indicates that the feedback mode is enabled, and (3) the one or more feedback resources for transmitting the sidelink feedback information corresponding to the physical shared sidelink channel are valid, or there are additional one or more feedback resources corresponding to the physical shared sidelink channel. Additional details and examples are described with reference to Embodiment 3-2.

10. The method of any of solutions 1-4, wherein the performing the sidelink communication based on the determination includes: transmitting the sidelink feedback information in case that following conditions are met: (1) determining that there is a conflict for a reserved resource for a physical sidelink shared channel PSSCH transmission, (2) one or more feedback resources for transmitting the sidelink feedback information corresponding to the PSSCH are valid, or there are additional one or more feedback resources corresponding to the reserved resource for PSSCH. Additional details and examples are described with reference to Embodiment 3-2.

According to some solutions, an apparatus for wireless communication comprises a processor configured to implement a method recited in any of above solutions.

One technical solution comprises a computer-readable storage medium having code stored thereupon, the code, upon execution by a processor, causing the processor to implement a method recited in any of above solutions.

FIG. 5 is a block diagram of an example implementation of a wireless communication apparatus 1200. The

methods

300 or 400 may be implemented by the apparatus 1200. The apparatus 1200 includes one or more processors, e.g., processor electronics 1210, transceiver circuitry 1215 and one or more antenna 1220 for transmission and reception of wireless signals. The apparatus 1200 may include memory 1205 that may be used to store data and instructions used by the processor electronics 1210. The apparatus 1200 may also include an additional network interface to one or more core networks or a network operator’s additional equipment. This additional network interface, not explicitly shown in the figure, may be wired (e.g., fiber or Ethernet) or wireless.

FIG. 6 depicts an example of a wireless communication system 1300 in which the various techniques described herein can be implemented. The system 1300 includes a base station 1302 that may have a communication connection with core network (1312) and to a wireless communication medium 1304 to communicate with one or more user devices 1306. The user devices 1306 could be smartphones, tablets, machine to machine communication devices, Internet of Things (IoT) devices, and so on. A sidelink communication may be established between different user devices, or UEs, e.g., as depicted by 1308 and 1310 representing a device to device communication from and to a wireless device.

The disclosed and other embodiments, modules and the functional operations described in this document can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structures disclosed in this document and their structural equivalents, or in combinations of one or more of them. The disclosed and other embodiments can be implemented as one or more computer program products, i.e., one or more modules of computer program instructions encoded on a computer readable medium for execution by, or to control the operation of, data processing apparatus. The computer readable medium can be a machine-readable storage device, a machine-readable storage substrate, a memory device, a composition of matter effecting a machine-readable propagated signal, or a combination of one or more them. The term “data processing apparatus” encompasses all apparatus, devices, and machines for processing data, including by way of example a programmable processor, a computer, or multiple processors or computers. The apparatus can include, in addition to hardware, code that creates an execution environment for the computer program in question, e.g., code that constitutes processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of them. A propagated signal is an artificially generated signal, e.g., a machine-generated electrical, optical, or electromagnetic signal, that is generated to encode information for transmission to suitable receiver apparatus.

A computer program (also known as a program, software, software application, script, or code) can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a standalone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. A program can be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document) , in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub programs, or portions of code) . A computer program can be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and interconnected by a communication network.

The processes and logic flows described in this document can be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus can also be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit) .

Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read only memory or a random access memory or both. The essential elements of a computer are a processor for performing instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto optical disks, or optical disks. However, a computer need not have such devices. Computer readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media and memory devices, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto optical disks; and CD ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.

While this document contains many specifics, these should not be construed as limitations on the scope of an invention that is claimed or of what may be claimed, but rather as descriptions of features specific to particular embodiments. Certain features that are described in this document in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub-combination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub-combination or a variation of a sub-combination. Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results.

Only a few examples and implementations are disclosed. Variations, modifications, and enhancements to the described examples and implementations and other implementations can be made based on what is disclosed.

Claims

A method of wireless communication, comprising:

determining, by a wireless device, using a rule, validity of one or more feedback resources configured in a time slot for transmission of sidelink feedback information; and

performing a sidelink communication based on the determination.
The method of claim 1, wherein, according to the rule, in case that the one or more feedback resources that are configured in a first resource pool overlap with a second resource pool in time domain, or the time slot that includes the one or more feedback resources in the first resource pool overlaps with the second resource pool, then the one or more feedback resources are considered to be invalid.
The method of claim 1, wherein, according to a rule, the validity is determined using an indication information configured in a first resource pool.
The method of any of claims 1-3, wherein the one or more feedback resources are included in a first slot and wherein,

in case that the one or more feedback resources are determined to be invalid, the method further includes determining a second slot that includes additional one or more feedback resources corresponding to the first slot.
The method of any of claims 1-4, wherein the performing the sidelink communication based on the determination includes:

in case that the one or more feedback resources are valid, then refraining from transmitting a physical sidelink shared channel in one or more symbols configured as the one or more feedback resources in the time slot, and refraining from transmitting the physical sidelink shared channel in a symbol immediately preceding the one or more symbols configured as the feedback resources in the time slot.
The method of any of claims 1-4, wherein the performing the sidelink communication based on the determination, includes:

In case that the one or more feedback resources are included in the time slot and the feedback resources are valid, or additional one or more feedback resources are included in the time slot, then refraining from transmitting a physical sidelink shared channel in one or more symbols configured as the one or more feedback resources in the time slot, and refraining from transmitting the physical sidelink shared channel in a symbol immediately preceding the one or more symbols configured as the one or more feedback resources in the time slot.
The method of any of claims 1-4, wherein the performing the sidelink communication based on the determination includes:

attempting to receive one or more associated sidelink feedback information in case that following conditions are met: (1) a physical sidelink shared channel (PSSCH) has been transmitted, (2) sidelink control information associated with the PSSCH indicates feedback mode enabled, and (3) one or more feedback resources for receiving the sidelink feedback information corresponding to the PSSCH are valid.
The method of any of claims 1-4, wherein the performing the sidelink communication based on the determination includes:

attempting to receive one or more associated sidelink feedback information in case that following conditions are met: (1) a physical sidelink control information (SCI) has been transmitted, (2) the SCI indicates one or more reserved resources for PSSCH in a resource pool, (3) an inter-UE coordination scheme 2 is enabled in the resource pool, and (4) one or more feedback resources for receiving the sidelink feedback information corresponding to the reserved resource for PSSCH are valid.
The method of any of claims 1-4, wherein the performing the sidelink communication based on the determination includes:

attempting to receive one or more associated feedback information in case that following conditions are met: (1) a physical sidelink shared channel (PSSCH) has been transmitted, (2) sidelink control information associated with the PSSCH indicates feedback mode enabled, and (3) one or more feedback resources for receiving the sidelink feedback information corresponding to the PSSCH are valid, or there are additional one or more feedback resources corresponding to the PSSCH.
The method of any of claims 1-4, wherein the performing the sidelink communication based on the determination includes:

attempting to receive one or more associated sidelink feedback information in case that following conditions are met: (1) a physical sidelink control information (SCI) has been transmitted, (2) the SCI indicates one or more reserved resources for a physical sidelink shared channel (PSSCH) in a resource pool, (3) an inter-UE coordination scheme 2 is enabled in the resource pool, and (4) one or more feedback resources for receiving the sidelink feedback information corresponding to the reserved resource for PSSCH are valid, or there are additional one or more feedback resources corresponding to the reserved resource for PSSCH.
The method of any of claims 1-4, wherein the performing the sidelink communication based on the determination includes:

in case that a feedback information reception occasion is associated with a sidelink control information (SCI) that indicates a cast type is groupcast 1 and one or more feedback resources in the feedback information reception occasion are valid, reporting as follows:

reporting, in case that the wireless device determines absence of feedback information reception for the feedback information reception occasion, an ACK value to a higher layer; otherwise, reporting a NACK value to the higher layer.
The method of any of claims 1-4, wherein the performing the sidelink communication based on the determination includes: for one or more feedback information reception occasions associated with a sidelink control information (SCI) that indicates a cast type is groupcast 1,

generating an ACK when the wireless device determines absence of feedback information reception for a last valid feedback information reception occasion from a number of feedback information reception occasions corresponding to one or more physical sidelink shared channel (PSSCH) transmissions; otherwise, generating a NACK; and transmitting a generated information by a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH) .
A method of wireless communication, comprising:

determining, by a wireless device, using a rule, validity of one or more feedback resources configured in a time slot for transmission of sidelink feedback information; and

performing a sidelink communication based on the determination.
The method of claim 13, wherein, according to the rule, in case that the one or more feedback resources that are configured in a first resource pool overlap with a second resource pool in time domain, or the time slot that includes the one or more feedback resources in the first resource pool overlaps with the second resource pool, then the one or more feedback resources are considered to be invalid.
The method of claim 13, wherein, according to a rule, the validity is determined using an indication information configured in a first resource pool.
The method of any of claims 13-15, wherein the one or more feedback resources are included in a first slot and wherein,

in case that the one or more feedback resources are determined to be invalid, the method further includes determining a second slot that includes additional one or more feedback resources corresponding to the first slot.
The method of any of claims 13-16, wherein the performing the sidelink communication based on the determination includes:

in case that the one or more feedback resources are valid, then refraining from receiving a physical sidelink shared channel in one or more symbols configured as the one or more feedback resources in the time slot, and refraining from receiving the physical sidelink shared channel in a symbol immediately preceding the one or more symbols configured as the feedback resources in the time slot.
The method of any of claims 13-16, wherein the performing the sidelink communication based on the determination, includes:

in case that the one or more feedback resources are included in the time slot and the feedback resources are valid, or additional one or more feedback resources are included in the time slot, then refraining from receiving a physical sidelink shared channel in one or more symbols configured as the one or more feedback resources in the time slot, and refraining from receiving the physical sidelink shared channel in a symbol immediately preceding the one or more symbols configured as the one or more feedback resources in the time slot.
The method of any of claims 13-16, wherein the performing the sidelink communication based on the determination, includes:

transmitting sidelink feedback information in case that following conditions are met: (1) a physical sidelink shared channel (PSSCH) is received, (2) sidelink control information indicates feedback mode enabled, and (3) the one or more feedback resources for transmitting a feedback information corresponding to the physical shared sidelink channel are valid.
The method of any of claims 13-16, wherein the performing the sidelink communication based on the determination includes:

transmitting sidelink feedback information in case that following conditions are met: (1) determining that there is a conflict for a reserved resource for a physical sidelink shared channel (PSSCH) transmission, and (2) the one or more feedback resources for transmitting the sidelink feedback information corresponding to the PSSCH are valid.
The method of any of claims 13-16, wherein the performing the sidelink communication based on the determination includes:

transmitting the sidelink feedback information in case that following conditions are met: (1) a physical sidelink shared channel is received, (2) sidelink control information associated with the physical sidelink shared channel indicates feedback mode enabled, and (3) the one or more feedback resources for transmitting the sidelink feedback information corresponding to the physical shared sidelink channel are valid, or there are additional one or more feedback resources corresponding to the physical shared sidelink channel.
The method of any of claims 13-16, wherein the performing the sidelink communication based on the determination includes:

transmitting the sidelink feedback information in case that following conditions are met: (1) determining that there is a conflict for a reserved resource for a physical sidelink shared channel PSSCH transmission, (2) one or more feedback resources for transmitting the sidelink feedback information corresponding to the PSSCH are valid, or there are additional one or more feedback resources corresponding to the reserved resource for PSSCH.
An apparatus for wireless communication, comprising:

a processor configured to implement a method recited in any of claims 1 to 22.
A computer-readable storage medium having code stored thereupon, the code, upon execution by a processor, causing the processor to implement a method recited in any of claims 1 to 22.